complete NSGarbageCollector class

git-svn-id: svn+ssh://svn.gna.org/svn/gnustep/libs/base/trunk@27653 72102866-910b-0410-8b05-ffd578937521

ChangeLog

@@ -4,6 +4,8 @@
 	Improve debug logging by including the address of the actual
 	handle concerned so that you can see which handle is doing what
 	when there are multiple handles in use.
+	* Source/NSGarbageCollector.m: Implement last methods.
+	* Headers/Foundation/NSGarbageCollector.h: Improve documentation.
 
 2009-01-21  Richard Frith-Macdonald <rfm@gnu.org>
 
@@ -114,9 +116,9 @@
 
 2009-01-14  Richard Frith-Macdonald <rfm@gnu.org>
 
-	* Source\NSGarbageCollector.m: Avoid compiler warning
-	* Source\pathconfig/pathconfig.mak.in: Fix syntax error in warning
-	* Headers\Additions\GNUstepBase\GSCategories.h: remove obsolete methods
+	* Source/NSGarbageCollector.m: Avoid compiler warning
+	* Source/pathconfig/pathconfig.mak.in: Fix syntax error in warning
+	* Headers/Additions/GNUstepBase/GSCategories.h: remove obsolete methods
 	* GNUmakefile: Fix order of includes
 	* Source/GSArray.m: Remove unused line from last change
 	* Source/NSNotificationCenter.m: Remove unused line

Headers/Foundation/NSGarbageCollector.h

@@ -54,18 +54,28 @@ extern "C" {
 - (void) collectExhaustively;
 
 /** Disables garbage collection until a corresponding call to -enable is made.
+ * NB. Calls to this method stack, and must be matched by the same number of
+ * calls to the -enable method.
  */
 - (void) disable;
 
-/** Disables collection for the area of memory pointed at.
+/** Makes the area of memory pointed at be uncollectable ... that is to say,
+ * the memory will not be collected by the garbage collector.  You must not
+ * explicitly free this memory unless you re-enable collection first.<br />
+ * Calls to this method do not stack, so callig it multiple times for the
+ * same pointer has the same effect as calling it once.
  */
 - (void) disableCollectorForPointer: (void *)ptr;
 
-/** Enables garbage collection prevously disabled by a calle to -disable
+/** Enables garbage collection prevously disabled by a call to the
+ * -disable method.  Since calls to -disable stack, you must make as
+ * many calls to -enable as to -disable in order to re-start collection.
  */
 - (void) enable;
 
-/** Enables collection for the area of memory pointed at.
+/** Enables collection for the area of memory pointed at, which must have
+ * previously been made uncollectable by a call to the
+ * -disableCollectorForPointer: method.
  */
 - (void) enableCollectorForPointer: (void *)ptr;      
 
@@ -78,6 +88,10 @@ extern "C" {
 - (BOOL) isEnabled;
 
 /** Returns a zone for holding non-collectable pointers.<br />
+ * Memory allocated in this zone will be seen by the garbage collector and
+ * collected (so it doesn't need to be freed explicitly), but the presence
+ * of pointers from the memory to other objectrs will not prevent those
+ * other objects from being collected.
  */
 - (NSZone*) zone;
 @end

Source/NSGarbageCollector.m

@@ -34,8 +34,9 @@ static unsigned			disabled = 0;
 #include <gc.h>
 
 #import	"Foundation/NSLock.h"
-static NSLock			*lock = nil;
-
+#import	"Foundation/NSHashTable.h"
+static NSLock		*lock = nil;
+static NSHashTable	*uncollectable = 0;
 #endif
 
 @implementation	NSGarbageCollector
@@ -82,8 +83,16 @@ static NSLock			*lock = nil;
 
 - (void) disableCollectorForPointer: (void *)ptr
 {
-  // FIXME
-  [self notImplemented: _cmd];
+#if	GS_WITH_GC
+  [lock lock];
+  if (uncollectable == 0)
+    {
+      uncollectable = NSCreateHashTableWithZone(NSOwnedPointerHashCallBacks,
+	0, GSScannedMallocZone());
+    }
+  NSHashInsertIfAbsent(uncollectable, ptr);
+  [lock unlock];
+#endif
   return;
 }
 
@@ -103,8 +112,14 @@ static NSLock			*lock = nil;
 
 - (void) enableCollectorForPointer: (void *)ptr
 {
-  // FIXME
-  [self notImplemented: _cmd];
+#if	GS_WITH_GC
+  [lock lock];
+  if (uncollectable != 0)
+    {
+      NSHashRemove(uncollectable, ptr);
+    }
+  [lock unlock];
+#endif
   return;
 }